Do nasal polyps and inverted papilloma have similar disorders in cell cycle regulation?

Establishment and genetic characterization of cell lines derived from proliferating nasal polyps and sinonasal inverted papillomas

To better understand the pathogenesis of nasal polyps (NPs) and sinonasal inverted papillomas (SIPs), we aimed to establish cell lines from fresh tissues of NPs and SIPs and characterize them. Primary cell cultures were obtained from two NP tissues (NP2 and NP3) and one SIP tissue (IP4). All the cells were polygonal in shape, expressed cytokeratin 14, and had normal diploid chromosome status. HPV58 DNA was detected in NP3. To obtain immortal primary cells, NP2 and IP4 cells were transduced with a combination of mutant CDK4, cyclinD1 and TERT. These cells were thereafter named NP2/K4DT and IP4/K4DT, respectively. HPV58-positive NP3 cells were transduced with TERT alone, the resulting cells named NP3/T. Phenotypic and genotypic identity of original tissues and derived cells was investigated. All the cell cultures with transgenes were confirmed to be derived from their parental cells and primary tumor tissues by analysis of short tandem repeats (STR) and maintained in vitro growth, genetic profiles and gene expression characteristics of the primary cells. These virtually immortalized cells, as well as the primary cells, have potential as in vitro models for studying the pathogenesis of NPs and SIPs and for preclinical study to develop new therapeutic agents.

Histopathological features of sinonasal inverted papillomas in chinese patients

OBJECTIVES/HYPOTHESIS

Nasal inverted papilloma (IP) is a benign tumor with high recurrence rates. Evidence of inflammation has been reported in IP in Caucasian studies. This study aimed to investigate the histopathological patterns and their associations with clinical characteristics in Chinese patients with IP.

STUDY DESIGN

Basic science study.

METHODS

IP tissues were obtained from 50 Chinese patients with unilateral IPs. Biopsies of inferior turbinate mucosa from 17 healthy subjects were used as controls. The histological patterns and severity of epithelial remodeling and inflammatory cell infiltration were evaluated and analyzed for associations with clinical characteristics.

RESULTS

Thirty-one percent of IP specimens were classified as grade I (mild remodeling) and 49% as grade II (moderate and severe remodeling). Concomitant inflammatory nasal polyps were found in 14 patients (28%). Recurrent IP was strongly associated with grade II (odds ratio: 5.81, 95% confidence interval: 1.34-25.18). Except CD4(+) T cells, quantities of neutrophils, macrophages, eosinophils, CD8(+) T cells, and FoxP3(+) T-reg cells were significantly elevated in IP. Of these, neutrophils were the predominant cell type in IP.

CONCLUSIONS

Inflammation may have potential roles in IPs and the higher grade of epithelial remodeling was associated with the recurrence of IPs.

LEVEL OF EVIDENCE

NA.

Inflammation and apoptosis in malignant transformation of sinonasal inverted papilloma: the role of the bridge molecules, cyclooxygenase-2, and nuclear factor κB

PURPOSE

This study examined the early events in the neoplastic progression of the sinonasal inverted papilloma to squamous cell carcinoma from the viewpoint of chronic inflammation and apoptosis.

MATERIALS AND METHODS

In total, 118 archival slides stained with hematoxylin and eosin from 45 patients were graded according to histopathology (grades I-IV). Their representative portions were transferred to a tissue microarray, sections of which were stained immunohistochemically for cyclooxygenase-2, p53, bax, bcl-2, and nuclear factor κB.

RESULTS

Cyclooxygenase-2 expression was positively correlated with histopathologic grade, with higher expression in advanced grades. p53s were detected in all cores from advanced grades (III, IV), but not in early grades (I, II). The expressions of nuclear factor κB, bax, and bcl-2 were not correlated with the grade.

CONCLUSIONS

A p53 mutation seems be a critical event for the malignant transformation of the sinonasal inverted papilloma. Cyclooxygenase-2-mediated inflammatory signals, activated as a consequence of the p53 mutation, may contribute to promoting the proliferation of the advanced sinonasal inverted papilloma.

Skull base inverted papilloma: a comprehensive review

Skull base inverted papilloma (IP) is an unusual entity for many neurosurgeons. IP is renowned for its high rate of recurrence, its ability to cause local destruction, and its association with malignancy. This paper is a comprehensive review of the reports, studies, and reviews published in the current biomedical literature from 1947 to September 2010 and synthesize this information to focus on its potential invasion to the base of the skull and possible intradural extension. The objective is to familiarize the clinician with the different aspects of this unusual disease. The role of modern diagnostic tools in medical imaging in order to assess clearly the limits of the tumors and to enhance the efficiency and the safety in the choice of a surgical approach is pointed out. The treatment guidelines for IP have undergone a complex evolution that continues today. Radical excision of the tumour is technically difficult and often incomplete. Successful management of IP requires resection of the affected mucosa which could be achieved with open surgery, endoscopic, or combined approach. Radio and chemotherapy were used for certain indications. More optimally research would be a multicenter randomized trials with large size cohorts.

Upregulation of Bcl-2 in nasal polyps from patients with cystic fibrosis

Background

Nasal polyps in patients with cystic fibrosis (CF) are believed to be phenotypically different than polyps affecting non‐CF patients. The aim of this study was to investigate differences in cell cycle regulatory mechanisms between these 2 groups. In this prospective study at a tertiary care academic medical center, multiple techniques were used to confirm the upregulation of antiapoptotic Bcl‐2 family proteins in CF polyps.

Methods

Nasal polyps were prospectively obtained from CF and non‐CF patients. The Sigma Panorama Protein Microarray for Cell Signaling was used to identify differences in protein expression between the 2 polyp groups. Western blot analysis confirmed altered expression of a subset of these proteins. Immunohistochemical staining was performed on archived tissue to further investigate B‐cell lymphoma 2 protein (Bcl‐2) expression. Following review by a pathologist, slides were digitized using an Aperio™ ScanScope XT system and staining intensity was quantified with the Positive Pixel Count algorithm. The mean staining intensity for each polyp group was compared.

Results

The protein microarray suggested a greater than 2‐fold upregulation of Bcl‐xl in CF polyps relative to non‐CF polyps. Western blot analysis confirmed the upregulation in CF polyps of Bcl‐2, a more commonly studied protein analog of Bcl‐xl. The CF polyp group was noted to have a higher quantitative intensity of immunohistochemical staining for Bcl‐2 compared to the non‐CF group (p < 0.05).

Conclusion

Through multiple modalities of protein investigation, we have demonstrated an upregulation of Bcl‐2 family proteins in CF polyps relative to polyps from non‐CF patients.

Prevalence of human papillomavirus, Epstein-Barr virus, p21, and p53 expression in sinonasal inverted papilloma, nasal polyp, and hypertrophied turbinate in Hong Kong patients

BACKGROUND

The purpose of this study of human papillomavirus (HPV), Epstein-Barr virus (EBV), p21, and p53 in sinonasal inverted papilloma (IP) was to help elucidate its pathogenesis.

METHODS

Seventy-three IPs, 48 nasal polyps, and 85 hypertrophied turbinates were subjected to HPV polymerase chain reaction (PCR) study. Seventy-three IPs, 30 nasal polyps, and 32 hypertrophied turbinates were subjected to EBV in situ hybridization (ISH), p21, and p53 immunohistochemical (IHC) studies.

RESULTS

HPV was positive in 3 of 73 IPs (4.1%). All specimens were EBV negative. In all, 99% of IPs showed strong and diffuse p21 nuclear reactivity. Most nasal polyps and hypertrophied turbinates showed weak to moderate immunoreactivity of the basal and parabasal cells. Only focal p53 immunoreactivity of the basal and parabasal cells was found in 19% of IPs and 40% of nasal polyps.

CONCLUSIONS

HPV prevalence of our IP is low. EBV is not present in IP. High p21 and low p53 expression in IP suggests a non-p53-dependent regulation pathway.

Pattern of Expression of Cell Cycle–related Proteins in Malignant Transformation of Sinonasal Inverted Papilloma

Background

It has been suggested that sinonasal inverted papilloma (IP) can progress to squamous cell carcinoma (SCC); however, mechanisms of malignant transformation are not fully understood. This study investigated alterations in the expression of cell cycle–related proteins in a multistep process of malignant transformation of IPs.

Methods

The expression of cell cycle–related proteins, including p53, p21, p16, and p63, was evaluated by immunohistochemistry in 21, 56, 7, and 18 cases of nasal polyps, IPs, IPs with dysplasia, and IPs with SCC, respectively. Furthermore, we determined the possible correlation between the expression of these proteins and clinicopathological variables in patients with IPs with SCC.

Results

Expression of p53 was found only in 8 of 18 IPs with SCC (44.4%). The frequency of p21 positivity was significantly higher in IPs with dysplasia (71.4%) and IPs with SCC (77.8%) compared with nasal polyps (0%) and IPs (12.5%). A p16 positivity was observed in 82.1% of IPs and 57.1% of IPs with dysplasia, whereas 83.3% of IPs with SCC showed an apparent loss of p16 protein expression. A p63 positivity was found in all specimens, but the percentage of positive cells was significantly increased in IPs with dysplasia and IPs with SCC compared with nasal polyps and IPs. There was no significant correlation between the expression of these proteins and clinicopathological variables, such as tumor stage, histological differentiation, and the proportion of malignant areas in patients with IPs with SCC.

Conclusion

Alteration of cell cycle–related proteins may contribute importantly to the malignant transformation from IP to SCC.

[Clinico-histopathological characteristic of inverted papilloma of nasal cavity and paranasal sinuses cases treated in Department of Laryngological Oncology UM of Lodz between 2002-2006--review of latest literature]

Authors introduced diagnostic procedures, clinico-morphological features and treatment results of 16 cases of nasal cavity and paranasal sinuses inverted papillomas treated surgically on Department of Laryngological Oncology of Medical University of Lodz between 2002-2006. References review, definition, classification, clinico-hiostopathological criteria and treatment methods of Schneiderian papilloma were introduced in study.

The prevalence of human papilloma virus infection in sinonasal inverted papilloma specimens classified by histological grade

BACKGROUND

Histological analysis suggests that inverted papilloma (IP) tumorigenesis may occur through a stepwise series of discrete events. The association between human papilloma virus (HPV) and IP has been described at varying incidences. The purpose of this study was to evaluate the prevalence of the HPV subtypes in a large series of IP specimens classified by histological grade.

METHODS

Fifty-seven paraffin-embedded specimens of Korean population were available for study. Each specimen was graded according to a four-stage histological grading system (stages I and II, benign IP; stage III, dysplastic IP; stage IV, carcinoma arising from IP). A representative section of IP specimen was isolated through laser capture microdissection (7.5- to 10-mum laser spot size). Subsequently, DNA extraction and HPV genotyping with the HPV DNA chip test (Biomed Lab Co., Seoul, Korea) was performed. The HPV DNA chip contained 22 type-specific probes that consisted of 15 high-risk subtypes and 7 low-risk subtypes.

RESULTS

Histological grading was as follows: 5, grade I; 23, grade II; 22, grade III; and 7, grade IV. Seven of 57 specimens (12.3%) showed HPV DNA. All of the HPV(+) cases showed HPV DNA in early grade (grades I and II) IP lesions. No higher grade (grades III and IV) IP tumors showed HPV DNA. Among the seven HPV(+) cases, five were high-risk subtypes and two were unspecified subtypes.

CONCLUSION

HPV infection, mainly high-risk subtypes, occurs in benign IP as an early event during the multistep tumorigenesis of IP. Cumulative other genetic insults may be required to progress from benign IP (grades I and II) to dysplastic IP (grade III) and carcinoma arising from IP (grade IV).